Polychlorinated metallocenes and their synthesis

ABSTRACT

Novel polychlorinated metallocenes are provided that have the following formulas: C5H5 mClmMC5H5 and (C5H5 nCln)2M, wherein M is iron, ruthenium or osmium, m is an integer from 3 to 5, inclusive, and n is an integer from 2 to 5, inclusive. The products are prepared by (1) reacting a monochlorometallocene or a 1,1&#39;&#39;-dichlorometallocene with an organolithium compound in the presence of a solvent, (2) recovering a 1-chloro-2lithiometallocene or a 1,1&#39;&#39;-dichloro-2,2&#39;&#39;-dilithiometallocene depending upon the starting material used, and (3) then reacting one of the latter compounds with a chlorination agent to obtain 1,2-dichlorometallocene or 1,1&#39;&#39;,2,2&#39;&#39;-tetrachlorometallocene. The lithiation step and the chlorination step can then be repeated one, two, 3 or more times, using in each reaction as the starting material the isolated chlorinated product from the prior reaction. The polychlorinated metallocenes are useful in preparing metallocene-containing polymers that are particularly suitable as ablative plastics for heat shields and structural laminates for light weight radiation shields. They also can be used to synthesize high temperature and/or high density fluids as well as for additives for lubricants and as flame retardant additives. The decachlorometallocenes are particularly useful because of their high resistance to oxidation.

United States Patent Hedberg et al.

[ POLYCHLORINATED METALLOCENES AND THEIR SYNTHESIS [72] Inventors:Frederick L. Hedberg, Tucson, Ariz.;

Harold Rosenberg, Dayton, Ohio [73] Assignee: The United States ofAmerica as representedbytheAirForce [22] Filed: Feb. 24, 1971 [2|]Appl.No.: 118,495

[52] U.S. Cl. ..260/429 CY, l06/l5 FP, 252/49.7, 260/2 M, 260/439 CY 5 1Int. Cl. ..co1r 15 02, c07r 15/00 [58] Held Search ..260/439 CY, 429 CY,649 R [56] References Cited UNITED STATES PATENTS 2,922,805 1/1960Kaufman ..260/439 CY 3,285,946 I l/l966 De Witt et al.. ...260/439 CY3,313,835 4/l967 Wilkus et al ...260/439 CY 3,422,129 l/l969 Rosenburg...260/439 CY 3,509, l 88 4/1970 Halasa et a]. ...260/439 CY 3,535,3 56l0/l970 Hartle et al ..260/439 CY OTHER PUBLICATIONS Nesme Yanov et al.Acad. of Sciences Bulletin, U.S.S.R. Jan- June 1956, pp. 749- 75] 51July 18, 1972 Primary ExaminerTobias E. Levow Assistant Examiner-A. P.Demers Arromeyi-larry A. Herbert, Jr. and Cedric H. Kuhn ABSTRACT Novelpolychlorinated metallocenes are provided that have the followingformulas: CJ-I CI MCJ-i, and (C,H CI,,),M, wherein M is iron, rutheniumor osmium, m is an integer from 3 to 5, inclusive, and n is an integerfrom 2 to 5, inclusive. The products are prepared by (l) reacting amonochlorometallocene or a l,l-dichlorometallocene with an organolithiumcompound in the presence of a solvent, (2) recovering alchloro-Z-lithiometallocene or a l, l '-dichloro-2 ,2dilithiometallocene, depending upon the starting material used, and (3)then reacting one of the latter compounds with a chlorination agent toobtain l,2-dichlorometallocene or l,l',2,2'-tetrachlorometallocene. Thelithiation step and the chlorination step can then be repeated one, two,3 or more times, using in each reaction as the starting material theisolated chlorinated product from the prior reaction. Thepolychlorinated metallocenes are useful in preparingmetallocene-containing polymers that are particularly suitable asablative plastics for heat shields and structural laminates for lightweight radiation shields. They also can be used to synthesize hightemperature and/or high density fluids as well as for additives forlubricants and as time retardant additives. The decachlorometallocenesare particularly useful because of their high resistance to oxidation.

22 Claims, No Drawings POLYCHLORINATED METALLOCENES AND THEIR SYNTHESISFIELD OF THE INVENTION This invention relates to polychlorinatedmetallocenes. In one aspect it relates to a process for the synthesis ofthese compounds.

BACKGROUND OF THE INVENTION While the thermal stability of metallocenesand metallocene polymers is well known, the utilization of metallocenederivatives for high temperature materials has been restricted by theirinstability toward chemical and air oxidation. The resistance of ametallocene toward chemical oxidation can be increased by theincorporation of electron-withdrawing substituents on the metallocenering. It has been shown that the eflect of two such substituents on theoxidation potential is approximately additive whether the substituentsare located heteroannularly or homoannularly. Although one might expecta substantial enhancement of oxidation resistance with the additionalsubstitution of the ferrocene ring by electronwithdrawing substituents,up to the present time this phenomenon has not been demonstrated sincesuch com pounds have not been available. Furthermore, no process hasbeen suggested whereby compounds, such as decachloroferrocene, can beprepared. The only known decal-substituted metallocene derivatives,namely l,l ',2,2'3,3',4,4',5,5'- decamethylferrocene and-decaethylferrocene, contain only electron-donating alkyl groups whichincrease the ease of oxidation of these compounds.

It is an object of this invention, therefore, to provide polychlorinatedmetallocenes that are highly resistant to oxidation.

Another object of the invention is to provide a process for preparingpolychlorinated metallocenes.

A further object of the invention is to provide polychlorinatedmetallocenes that are stable at elevated temperatures.

Other objects and advantages of the invention will become apparent tothose skilled in the art upon consideration of the accompanyingdisclosure.

SUMMARY OF THE INVENTION In one embodiment the present invention residesin a polychlorinated metallocene selected from compounds having thefollowing structural formulas:

wherein M is a metal selected from the group consisting of iron,ruthenium and osmium; R is Cl, 1, OCH- OQH, Li, or COOH, and R k and Rare each Cl or H, the R, group being l, methoxy, ethoxy, Li or COOH onlywhen R,,R,-, and R, are each Cl, and when a R ,R or R is Cl, each Clatom is adjacent to a Cl atom.

Examples of compounds according to formula (1) includel,l.2,2'-tetrachloroferrocene: 1.I2.2l,l',2,2'.3.3'-hcxachloroferrocenml.l '.2,2',3 .3.4.4'-octachloroferrocene; l, 1'2 ,2 ,3 .3 ,4,4' 5.5'-decachloroferrocene; 1,1 d iiod ooctachloroferrocene; 1.1'-dimethoxyoctachloroferrocene; l,l diethoxyctachloroferrocene; 1.]'-dilithiooctachloroferrocene; octachloroferrocene-l .l '-dicarboxylicacid: and the corresponding derivatives of ruthenocene and osimocene.

Examples of compounds according to Formula (2) include 1,2,3-trichloroferrocene; l ,2,3 ,4-tetrachloroferrocene, l,2,3,4,5pentachloroferrocene; and the corresponding derivatives of ruthengceneand osrnocene.

The preferred metallocenes are those that have the structure of Formulal i.e., compounds in which hydrogen atoms on both rings have beensubstituted with chlorine atoms. And of the preferred compounds,decachloroferrocene and decachlororuthenocene are the more desirablebecause of their outstanding thermal stability and high resistance tooxidation as well as their ability to function as intermediates in thepreparation of important derivatives.

in another embodiment, the present invention resides in a process forpreparing the polychlorinated metallocenes. Broadly speaking, theprocess comprises the following steps: (I) reacting a chlorinatedmetallocene selected from the group consisting of l,l-dichloroferrocene, l,l dichlororuthenocene, l,l '-dichlorosmocene,chloroferrocene, chlororuthenocene, and chlorosmocene with anorganolithiurn compound in the presence of a solvent for the chlorinatedmetallocenes; (2) adding a chlorinating agent to the resulting reactionmixture; (3) and recovering a reaction mixture containing al,l',2,2'-tetrachlorometallocene when the chlorinated metalloceneselected is a dichlorometallocene and a 1,2-dichlorometallocene when thechlorinated metallocene selected is a ehlorometallocene. The chlorinatedmetallocene is thereafter recovered from the reaction mixture as theproduct of the process. The separation can be accomplished by anysuitable means. However, it is usually preferred to carry out theseparation by (a) filtering the reaction mixture, e.g., by passing itthough a bed of alumina, (b) concentrating the filtrate to dryness, (c)fracu'onally sublimining the residue to remove any remaining solvent,and (d) recovering the product by recrystallization from an aliphatichydrocarbon such as hexane.

When it is desired to obtain a chlorinated metallocene which is furthersubstituted with chlorine atoms, the L! 2,2- tetrachlorometallocene orthe 1,2, dichlorometallocene obtained as described above is reached withan organolithium compound in the presence of a solvent. The chlorinatingagent is then added to the resulting reaction mixture, and there isrecovered a reaction mixture containing a l,l',2,2,3,3'-hexachlorometallocene when 1,] ',2,Z'Jetrachlorometalloceneis the starting material and a 1,2,3-trichlorometallocene whenl,2-dichlorometallocene is the starting material. The lithiation,chlorination and separation steps are repeated two more times to obtain(1) a 1,] ,2,2',3,3',4,4'-octachlorometallocene orl,2,3,4-tetrachlorometallocene and (2) a l,l,2,2',3,3',4,4',$,5-decachlorometallocene or al,2,3,4,5-pentachlorometallocene.

As described hereinabove, the higher chlorine-containing metallocenesare prepared using as a starting material the next lowerchlorine-containing metallocene. However, in a preferred method forpreparing, for example, decachloroferrocene and pentachloroferrocene,the starting material is not isolated prior to the lithiation andchlorination steps. Thus, the reaction mixture recovered from theinitial lithiation and chlorination steps is merely treated to removeorganolithium compound and solvent, for example, by passing it through acolumn of alumina and removing the solvent by sublimation. The residuewithout further treatment is then subjected to the lithiation andchlorination steps. The described procedures are repeated three moretimes until the decachloroferrocene or pentachloroferrocene product isobtained. This latter process is the preferred one for preparingdecachlorometallocenes and pentachlorometallocenes since much higheryields are obtained. Furthermore, the process is simplified. therebyrendering it less expensive to conduct since it is unnecessary toisolate a product after each series of lithiation and chlorinationsteps.

The reactions that occur in the four stage process for preparingdecachloroferrocene are shown by the following equations:

Solvent. 1

Solvent C hlorinating Agent (III) C! (Ill Liam e Solvent Cl-tCl c1Cl@-Cl 01-6-01 Cl- C. l

RLi Ohlorinnting (3 I 0 Cl Agent As seen from the foregoing, each of thefour stages (l-lV) involves a lithiation step and a chlorination step.According to 1.1 ',2,2'-tetrachloroferrocene,

the illustrated process,

tachloroferrocene and l,l ,2,2',3,3',4,4',5,5'-decachloroferrocene arerecovered as the product of each successive stage with each of the firstthree named products serving, respectively, as the starting material forthe next successive stage.

ing equation:

t, l, 2, 2. 3, 8' 4, 4 5, fi decatlhlorofsrroceno -Cl O @9 i 1. am i l2. gmplrtinutlmt (I) in the equation x is an integer equal to the numberof stages in the process and is at least 4 and is preferably equal to 5when preparing decachloroferrocene. Furthermore, when preparing thedecachlorometallocene by the direct process, a metallocene per se can beused as the starting material and six stages (F6) are preferablyconducted. Each stage of the process consists of two steps, i.e., l) thelithiation step (RLi) followed by (2) the chlorination step(chlorinating agent). Upon completion of the fourth, fifth or sixthstage, the decachlorotnetallocene is recovered from the reaction mixtureby any suitable means, such as by sublimation followed byrecrystallization from a solvent.

The above discussion has been concerned with the preparation ofpolychlorinated ferrocenes in which l,l'-dichloroferrocene is used asthe initial starting material. As a result chlorine atoms aresubstituted for hydrogen atoms on both ferrocene rings. Whenchloroferrocene is utilized as the initial starting material,substitution occurs on only one ferrocene ring. The same reactions occuras represented above except that chlorine atoms replace hydrogen atomson only one of the rings. Thus, in the indirect process when startingwith chloroferrocene, l,2-chloroferrocene, l,2,3chloroferrocene,l,2,3,4-chloroferrocene, and l,2,3,4,5-chloroferrocene are recovered asthe product of each successive stage with each of the first three namedproducts serving, respectively as the starting material for the nextsuccessive stage.

The structure of the polychlorinated ferrocenes shown and describedabove has been substantiated by elemental analyses, GLC analyses, massspectral analyses and the nmr spectra of the compounds. The molecularion peaks, isotopic distributions, and fragmentation patterns were allin accord with the disclosed structures. The mass spectral fragmentationpatterns showed the distribution of the chlorine atoms between therings. The distribution of the chlorine atoms within the rings wasobtained from the nmr spectra of the compounds. The nmr absorbance peaksfor the compounds show that lithiation occurs in a position alpha to achlorine atom. For l,1',2,2',3,3 ',4,4'-octachloroferrocene andl,2,3,4-tetrachloroferrocene, there is marked downfield shift in theabsorbance of the lone proton in the substituted ring or rings. Thisproton must necessarily be flanked on each side by a chlorine atom inthese two compounds. This observation coupled with the fact that thecenter alpha proton does not vary from the compounds containing a lessernumber of chlorine atoms establishes that each of the substituted ringprotons in l,l ',2,2'-tetrachloroferrocene,l,l',2,2',3,3'-hexachloroferrocene, l,2-dichloroferrocene andl,2,3-trichloroferrocene is flanked by a single chlorine atom. Such asituation can only exist if the chlorine atoms are all located adjacentto one another.

Organolithium compounds that can be employed in the process of thisinvention correspond to the formula RLi, where R is a phenyl radical oran alltyl radical, preferably containing from one to four, inclusive,carbon atoms. Examples of suitable organolithium reagents includephenyllithium, methyllithium, ethyllithium, and n-butyllithium. It isgenerally preferred to employ n-butyllithium. While theoretically l or 2mols of the organolithiurn compound per mol of the chlorinatedmetallocene can be used depending upon whether I or 2 hydrogen atoms areto be replaced with a lithium atom, it is usually preferred to utilizean excess ofthe organolithium. Thus, 1.1 to 2.5 mols of organolithiumper mol of the metallocene compound are used when the substitutionoccurs in one of its rings and 2.2 to 5.0 mols per mol of themetallocene compound when the substitution takes place in both of itsrings.

in conducting the first step of the process, i.e., the lithiation stepof the first stage, it has been found to be advantageous to add with theorganolithium compound, or immediately thereafter, an aliphatic diamine.Examples of suitable diamines include ethylenediamine, N,N,N,N'-tetramethylethylenediamine, and the like. it has been found thataddition of the diamine, which forms a complex with the organolithiumcompounds, assures that a lithium atom will be substituted next to achlorine atom. The addition of an aliphatic diamine to the first step isparticularly important in the practice of the indirect process in whicha particular polychlorinated metallocene, e.g., l,l',2,2'-tetrachloroferrocene or l,2-dichloroferrocene, is separated fromthe reaction mixture of the first stage for use as the starting materialin the lithiation step of second stage. Generally one mol of thediamine, or a small excess such as l.] mol, is added per mol of theorganolithium compound.

As a chlorinating agent it is preferred to employ a 1,2- dichloroethane.Examples of suitable compounds include 1,2 dichloroethane,hexachloroethane, 1,2- dichlorotetrafluoroethane, l,2-dichlorotetrabromoethane, and the like. Hexachloroethane is thepreferred chlorinating agent. As with the organolithium compound, it ispreferred to employ an excess amount of the chlorinating agent. Thus,from 2 to 10 mols of the chlorinating agent are usually used for eachmol of the metallocene compound. When the metallocene has a lithium atomon one only ring, lesser amounts, e.g., 2 5 mols of the chlorinatingagent can be used. However, greater amount, e.g., 4 to 10 mols of thechlorinating agent are generally employed when one lithium atom isattached to each ring of the metallocene.

The lithiation steps are conducted in the presence of a solvent for thechlorinated metallocenes. An ether solvent has been found to beparticularly suitable, examples of which include diethylether,tetrahydropyrane, and tetrahydrofuran. It is usually preferred to usetetrahydrofuran. However, aliphatic hydrocarbons, such as thosementioned below can be used, particularly in the first stage of theprocess. The organolithium compound is usually added to the chlorinatedmetallocene an aliphatic hydrocarbon solvent. Examples of such solventsin clude pentane, hexane, heptane, octane and the like. Thus, in thelithiation step a dual solvent system is generally used, i.e., a mixtureof an ether and an aliphatic hydrocarbon, both of which are inert to thereaction involved. The amount of solvent used is that which issufficient to dissolve the ingredients. it is usually several volumes ascompared to the volume of the ingredients in order to permit efficientstirring of the reaction mixtures.

The chlorination steps are also generally conducted in the presence of asolvent. The solvent used is preferably an aliphatic hydrocarbon of thetype used in the lithiation steps, and as a practical matter the samesolvent is employed in both steps. The criteria as to the amount ofsolvent used in the lithiation steps apply generally to the amount usedin the chlorination steps. it is to be understood, however, that thechlorination steps can be conducted in the absence of a solvent.

in initial stages prior to the last stage of the process, both directand indirect, the temperature during the lithiation and chlorinationsteps is maintained in the range of about to 40 C., preferably in therange of about [5 to 25" C. During the last stage of the process, bothdirect and indirect, the tempera ture is maintained in the range ofabout to 10 C., preferably from -S to 5 C. All steps of the process arecarried out in an inert atmosphere, such as under an atmosphere ofnitrogen or argon.

The 1,1, 2,2, 3,3, 4,4, 5,5'-decachlorornetallocenes prepared by theprocess of this invention undergo heteroannular dilithiation uponreaction with an organolithium compound, such as n-butyllithium, to givel,l '-dilithiooctachlorometallocenes. These compounds are versatileintermediates which can, in turn, be used in providing a variety ofsubstituted perchlorometallocenes. For example, they can be hydrolyzedto form l,l', 2,2, 3,3, 4,4'-octachlorometallocenes which are useful asmonomers. Thu, chlorine-cantalolng polymers can be prepared bypolymerizing the materials in the presence of a suitable catalyst. Thel,l-dilithiooctachlorometallocenes can also be reacted with iodine toform l,l'-diiodooctachlorometallocenes and with carbon dioxide to formoctachloromctallocene-l,l' dicarboxylic acids. The Iodine-containingcompounds are also useful a monomers, e.g., in polymerlntions in thepresence of a copper catalyst to prepare chlorine-containing metaliocenepolymers. The dlcarboxylic acids can be reacted with an alcohol orpolyol to form esters having a high chlorine content.

The decachlorometallocenes upon reaction with sodium methoxide inmethanol form l,l'-dimethoxyoctachlorometallocenes. Similarly, whendecachlorometallocenes are reacted with sodium ethoxide in ethanol,l,l'-diethoxyoctachlorometallocenes and isomers thereof are formed. inaddition to the foregoing, the polychlorinated metallocenes of thisinvention are useful as lubricant additives and as flame retardantadditives for polymeric materials.

in the foregoing discussion, ferrocenes have been specifically referredto in many instances. However, it is to be understood that the inventionis not limited to such compounds but is applicable as well toruthenocenes and osmocenes. Furthermore, where reference has been madeto metallocenes, it is to be understood that ferrocenes, ruthenocenesand osmocenes are the intended compounds.

A better understanding of the invention can be obtained by referring tothe illustrative examples described below that are not intended,however, to be unduly limitative of the invention. The runs described inthe examples were carried out under an atmosphere of high puritynitrogen. The n-butyllithium solution in hexane used was found bytitration to be 1.5 molar. The chloroferrocene and the l,l'dlchloroterrocene were prepared from ferroceneboronlc acid and 1,1'-ferrocenediboronic acid, respectively, according to proceduresdescribed by A. N. Nesmeyanov et al. in Doklady Akad. Nauk SSSR,l00,l099 (i955). Gas liquid chromatography (GLC) analyses were performedon either an F&M Model 500 chromatograph or an F&M Model 402chromatograph. Molecular weight determinations were carried out with amass spec trometer. Chlorine isotope distributions obtained for theferrocene derivatives and chlorine-ruthenium isotope distribu tionsobtained for the ruthenocene derivatives were all in agreement with thecalculated isotope patterns. For those compounds for which an exact massdetermination was not made, the correct nominal mass was obtained forall peaks in the molecular ion cluster. Percentages where used are inweight percent.

EXAMPLE 1 Preparation of l,l 2,2'-tetrachloroferrocene A solution ofl,l-dichloroferrocene l5.7g, 0.06l 6 mol) in hexane (900 ml) was stirredat 23 C. while a solution of n-butyllithium in hexane ml, 0.l5 mol) wasadded followed by the addition of tetramethylethylenediamine (TMEDA)l8.6g, 0.16 mol). The resulting reaction mixture was stirred for 50minutes at 23 C. after which it was added over a 35 minute period to astirred solution of hexachloroethane (47g, 0.20 mol) in hexane (300 ml).After completion of the addition, stirring was continued for 5 minutes,and the reaction mixture was filtered through a bed of alumina. Thefiltrate was concentrated to dryness and the residue was fractionallysublimed. After removal of hexachloroethane at 45 C. (0.25 mm of Hg),the product was sublimed at l20 to l25 C. (0.25 mm of Hg). The sublimateweighed l6.55g and by GLC analysis consisted of trichloroferrocene 2%)and l,l', 2,2- tetrachloroferrocene 98%). This represents an 83 percentyield of the latter compound. Recrystallization from hexane produced1,1, 2,2'-tetrachloroferrocene having a melting point of 147 C. Analysisof this product gave the following results:

Calculated (C l'l Cl,

Preparation of 1,1, 2,2, 3,3'-Hexachloroferrocene A solution of l, l',2,2'-tetrachloroferrocene (7.733, 0.0238 mol) in dry tetrahydrofuran(THF) (700 ml) was stirred at C. while a solution of n-butyllithium inhexane (100 ml, 0.15 mol) was added. The resulting reaction mixture wasstirred for 2.5 hours at 15 C. and then added over a -minute period to asolution of hexachloroethane (48g, 0.20 mol) in hexane (400 ml). Afteraddition was completed, stirring was continued for 5 minutes, and thereaction mixture was filtered through a bed of alumina. The filtrate wasconcentrated to dryness and the residue was fractionally sublimed. Theproduct weighed 8.83g and by GLC analysis consisted ofpentachlorot'errocene (7%), 1,1, 2,2, 3,3'-hexachloroferrocene (92.5%),and heptachloroferrocene (0.5%). Recrystallization from hexane gave6.17g of 1,1, 2,2, 3,3'-hexachloroferrocene, representing a yield of 66percent. The melting point of the product was 191 C. Analysis of theproduct gave the following results:

Calculated (C H CL;

Fe),% Found,%

C 30.58 31.03; 30.97 H 1.03 1.03; 1.03 Cl 54.17 53.65; 53.78 Fe 14.22l4.1l7', 14.92 Mol. Wt. 391.7764 391.7755

EXAMPLE [11 Preparation of 1,1, 2,2,3,3', 4,4-OctachloroterroceneCalculated (C ,,H,Cl,.

Fe),1' Found, k

C 26.02 26.23; 26.09 H 0.44 0.57; 052 C1 61.45 61.90; 61.84 Fe 12.101l.9l;ll.92 Mol. Wt. 461.6955 461.6933

EXAMPLE 1V Preparation of 1,1 2,2, 3,3, 4,4, 5.5'-Decachloroferrocene Asolution of 1,1 2,2, 3,3, 4,4'-octachloroferrocene (0.584g, 0.00126 mol)in dry THF (130 ml) was stirred at 0 C. for 1 hour while a solution ofn-butyllithium in hexane (2.5 ml, 0.0037 mol) was added. The resultingreaction mixture was stirred at 0 C. for 1 hour after whichhexachloroethane (2.37g, 0.010 mol) was added. Stirring was continuedfor 15 minutes and the reaction mixture was then filtered through a bedof alumina. The filtrate was concentrated to dryness and dry-columnchromatography of the residue (hexane as eluent) produced 0.623g ofmaterial which by GLC analysis consisted of octachlorolerrocene 1%),nonachlorolerrocene (8%), and decachloroferroeene (91%). This mixturewas dissolved in carbon tetrachloride and stirred with concentratednitric acid for 29 hours. The carbon tetrachloride layer, which formedupon standing, was separated and passed through a column of alumina togive 0.565g of decachloroferroeene having a rnelting point of 245 to 246C. This represents a yield of percent while the overall yield ofdecachloroferrocene was 7 percent. The product was analyzed with thefollowing results:

Calculated (C CI F e),% Found,%

C 22.64 22.82; 22.85 Cl 66.83 66.31, 66.32 Fe 10.53 9.75; 9.72 M01. Wt.529.6175 529.6120

EXAMPLE V Preparation of Decachlorot'errocene l,l'-Dichloroferrocene(17.47g, 0.0686 mol) in hexane 1500 ml) was stirred at 23 C. while asolution of n-butyllithiurn (133 ml, 0.20 mol) followed by TMEDA (23g,0.20 mol) was added. The resulting reaction mixture was stirred at 23 C.for 1 hour and then cooled to 70 C. Hcxachloroethane (71g; 0.30 mol) wasadded and the temperature was allowed to rise to 10C. over a 1-hourperiod. The reaction mixture was then extracted with water, and thehexane layer separated and concentrated to dryness. The hexachloroethanewas removed by sublimation and the crude residue was reacted withn-butyllithium (200 ml, 0.30 mol) in dry THF (1 1) at 0 C. for 3 hours.The reaction mixture was cooled to -70 C., and hexachloroethane (95g,0.40 mol) was added. The temperature was allowed to rise to 5 C. over a1-hour period, and the reaction mixture was then passed through a columnof alumina (THF as eluent). The solvent was distilled from the eluate at23 C. in vacuuo and the hexachloroethane was removed by sublimation. Theresidue was subjected three more times to the above described reactions(lithiation and chlorination) and the corresponding work-up procedures,the sole modification being a decrease in the lithiation times to 2.5hours, 1 hour and 30 minutes for the final three runs. The crude productfrom the last reaction, after removal of hexachloroethane bysublimation, was recrystallized from hexane to give 13.0g ofdecachloroferroccne of 96 percent purity by GLC. The residue from themother liquor was stirred with a mixture of carbon tetrachloride andconcentrated nitric acid for 5 hours and chromatographed on alumina togive an additional 2.2g of decachloroferrocene of 98 percent purity byGLC. The amount of product obtained (15.2g) represented a 42 percentyield ofdecachlorolerrocene.

ln Examples l-lV, decachloroferrocene and the several intermediates wereproduced by the indirect method. Example V demonstrates the use of thedirect process in the preparation of decachloroferrocene. Because of thehigher yields that can be obtained, the direct process is preferred inpreparing decachlorometallocenes. Furthermore, the direct process issimpler and less expensive to practice because it is unnecessary torecover a pure intermediate after each chlorination step.

EXAMPLE Vl A solution of ruthenocene (ll.55g, 0.05 mol) in hexane (i000ml) was stirred and heated at reflux temperature while a solution ofn-butyllithium in hexane (I I ml, 0.15 mol) was added. Heating wasdiscontinued and TMEDA (22 ml, 0.15 mol) was added at a rate whichmaintained reflux. The reaction mixture was refluxed for 1 hour and thencooled to 20 C. Hexachloroethane (47.4g, 0.20 mol) was added and thetemperature was allowed to rise to C. over a period of 30 minutes. Afterremoval by filtration of the solids present, the hexane filtrate waspassed through a column packed with alumina. Hexachloroethane was elutedwith petroleum ether, and the mixture of chlorinated ruthernocenes waseluted with carbon tetrachloride. The crude mixture. after removal ofsolvent, was subjected to the same reaction as described above, exceptthat lithiation was carried out at 23 C. instead of a refluxtemperature. The crude product obtained was dissolved in THF (500 ml)and stirred at 70 C. while a solution of n butyllithium in hexane (200ml, 0.30 mol) was added. The reaction mixture was warmed to 0 C. over a30-minute period, stirred at 0 C. for 2 hours, and cooled to 70 C.Hexachloroethane (95g, 0.40 mol) was added, and the temperature wasallowed to rise to 10 C. over a 1-hour period. The entire reactionmixture was then absorbed on alumina, and the THF removed byevaporation. Dry-column chromatography was carried out on the driedalumina to remove hexachloroethane upon elution with petroleum ether andto provide a crude mixture of chlorinated ruthenocenes upon elution withcarbon tetrachloride. This mixture was subjected four more times to theabove-described reactions in THF (lithiation and chlorination and thelatter work-up procedure at the following lithiation temperatures andtimes: 0 C for 1 hour, 0 C. for l hour, 70 C. for 30 minutes, and 70 C.for 30 minutes. The product from the final reaction was recrystallizedfrom heptane to give 4.2g of decachlororuthenocene having a purity 99percent by GLC. This represented a product yield of 14 percent. Theproduct showed some evidence of sublimation above 300 C. and decomposedat 360 to 365 C. Analysis of the product gave the following results:

The molecular ion cluster was a unique and complex pattern from 566 to586 mass units which was identical with the pattern calculated for thecompound.

EXAMPLE Vll Preparation of 1,2-Dichloroferrocene A solutionofchloroferrocene (4.42g, 0.02 mol) in dry THF 125 ml) was stirred at 0C. while a solution of n-butyllithium in hexane (30 ml, 0.045 mol) wasadded. The resulting reaction mixture was stirred at 0 C. for L5 hoursand then cooled to 78 C. A solution of hexachloroethane l4.2g, 0.060mol) in hexane (50 ml) was added, and the reaction mixture was thenallowed to warm to 0' C. over a 30 minute period. Subsequent work-upconsisted of dry-column chromatography on alumina with hexane as theeluent. The excess hexachloroethane eluted first, followed by a yellowband from which, after solvent removal, there was obtained 3.48g ofmaterial determined by GLC to consist of 1,2-dichloroferrocene (81%) anda material 19%) determined by mass spectral analysis to be atriehloroferrocene. Recrystallization from methanol providedLZ-dichloroferrocene having a melting point of 88 to 90 C. Analysis ofthe product gave the following results:

10 Calculated (C l'i Cl,

Fe),% Found,%

C 47.l l 47.39; 47.22 3.16 3.; 3.05 Mel. Wt. 253.9351 253.9355

EXAMPLE Vlll Preparation of l,2,3-Trichloroferrocene The procedure usedwas the same as that described in Example VII in preparingl,2-dichloroferrocene. From 4.50g of 1,2-dichloroferrocene, there wasobtained $.l2g of material which by GLC analysis consisted of1,2-dichloroferrocene (3%), 1,2,3-trichloroferrocene (86%), andtetrachloroferrocene (l l%). Recrystallization from methanol providedl,2,3-trichloroferrocene having a melting point of 103.5 to 104.5 C.Analysis of the product gave the following results:

Calculated (C JI CI,

Fe),% Found,%

C 4|.5l 4l.57-,4l.46 H 2.44 2.47; 2.42 Moi. Wt. 287.8961 287.8982

EXAMPLE [X Preparation of l,2,3,4-tetrachloroferrocene The procedureused was the same as that described in Example Vll. From 0.70g of1,2,3-trichloroferrocene, there was obtained 0.62g of material which byGLC analysis consisted of l,2,3-trichloroterrocene l0%),l,2,3,4-tetrachloroferrocene and pentachloroferrocene (10%). PreparativeGLC provided l,2,3,4-tetrachloroferrocene having a melting point of 8|to 82 C. Analysis of the product gave the following results:

Preparation of l,2,3,4,5-Pentachloroferrocene A mixture ofl,2-dichloroferrocene (25%) and l,2,3- trichloroferrocene (75%) wassubjected to the reaction procedure described in Example Vll to give amaterial consisting of 1,2,3-trichloroferrocene (42%),l,2,3,4-tetrachloroferrocene (29%) and pentachloroferrocene (29%).Repetition of the reaction with this mixture gave a material consistingof l,2,3,4-tetrachloroferrocene (42%) and l,2,3,4,5-pentachloroferrocene(58%) together with a trace of hexachloroferrocene. This mixture wasreacted in dry ethanol with excess n-butyllithium-hexane solution,followed by addition of hexachloroethane at 0 C. Dry-columnchromatography provided a mixture of tetrachloroferrocene (20%),l,2,3,4,5-pentachloroferrocene (70%) and hexachloroferrocene (10%).Recrystallization from methanol provided l.2,3,4,5-pentachloroferrocenehaving a melting point of 143 to M4 C. Analysis of the product gave thefollowing results:

EXAMPLE XI A suspension of decachloroferrocene (1.00g, 0.00190 mol) indry diethylether (175 ml) was stirred at 70 C. while a solution ofn-butyllithium in hexane (3.8 m1, 0.0057 mol) was added. After 30minutes at 70 C., an orange solution was present. Continued stirring for30 minutes more produced a voluminous precipitate. Iodine (2.54g, 0.010mol) was added, and the reaction mixture was warmed to 5 C. over a 40-minute period. Passage through a bed of alumina (methylene chloride aseluent) followed by removal of solvent produced l.3$g (99%) of 1,1'-diiodooctachloroferrocene having a purity of 98 percent of GLC.Recrystallization from hexane gave a product having a melting point of240 C. Analysis of the product gave the following results:

Calculated (C C1,,l,Fe )3: Found,%

Preparation ofOctachloroferrocene-1,1'-dicarboxylic acid A solution ofdecachloroferrocene (0.80, 0.00151 mol) in dry THF I25 ml) was stirredat 70 C. while a solution of nbutyllithium in hexane (30 ml, 0.0045 mol)was added. The resulting deep orange solution was stirred for minutes at70 C. and then a molar excess of Dry Ice (C0,) was added. The reactionmixture was stirred for 20 minutes while warming to 0 C. and then pouredinto 500 ml of water and extracted with hexane. The aqueous layer wasacidified with 10 percent hydrochloric acid, resulting in a voluminousprecipitate which was collected, washed with water and dried to give0.81 g (97 percent) of octachloroferrocene-Ll '-dicarboxylic acid afterrecrystallization from a mixture of THF and benzene. The product had amelting point of 245" C. Analysis of the product gave the followingresults:

The infrared spectrum (KBr) showed an intense C 0 band at 1,680-1 ,695cm".

EXAMPLE X111 Preparation of 1,1 '-Diiodooctachlororuthenocene A solutionof decachlororuthenoccne (0170g, 0.0012 mol) in dry THF 125 ml) wasstirred at 70 C. while a solution of n-butyHithium in hexane (2.4 ml,0.0036 mol) was added. Afier stirring at -70 C. for minutes, iodine(2.0g, 0.0080 mol) was added, and the reaction mixture was warmed to 10C. over a period of 40 minutes. Passage through a bed of aluminafollowed by removal of solvent left 0.89 (98%) of 1,1-diiodooctachlororuthenocene. After recrystallization from hexane, thematerial showed sublimation above 300 C., darkening above 325 C. andiodine elimination above 350 C. Analysis of the product gave thefollowing results:

Calculated (C,,,Cl.l,Ru),% Foundfb l 33.19 Ru 13.21

EXAMPLE XIV Lithiation and Hydrolysis of Decschloroferrocene A solutionof decachloroferrocene (0.41 lg, 0.00074 mol) in dry THF (75 ml) wascooled with liquid nitrogen until frozen. A solution of n-butyllithiumin hexane (2.0 ml, 0.0030 mol) was added, and the reaction mixture wasallowed to warm, with stirring, over a 15 minute period to 40' C.Distilled water (2 ml, 0.09 mol) was added giving a voluminousprecipitate. Stirring was continued for 10 minutes while the mixture wasallowed to warm to 0' C. The mixture was then filtered and the filtrateconcentrated to dryness. Drycolumn chromatography of the residue onalumina provided 0.359g of material which by GLC analysis consisted ofpure 1,1, 2,2, 3,3, 4,4'-octachloroferrocene. GLC retention time,melting point and infrared spectrum were identical with those of anauthentic sample.

EXAMPLE XV Reaction of Decachloroferrocene with Sodium Methoxide Amixture of decachloroferrocene (0.21 g, 0.00040 mol) and sodiummethoxide (0.5g, 0.01 mol) in methanol ml) was stirred and refluxed for18 for hours. Repeated analysis of the reaction mixture during thisperiod was carried out by thin-layer chromatography (TLC) on silica gelwith carbon tetrachloride as developer. A steady decrease in theintensity of the starting material (R QBS) was noted, accompanied by theformation of two new compounds of ii -0.62 and Ry-0.40, respectively.The formation of the latter compound at first appeared to be much slowerthan that of the former. However, the ration of the intensities of thelatter to the former compound increased with time. Afler 18 hours, thereaction mixture was cooled, absorbed on alumina, and chromatographed onalumina. Two bands were eluted with carbon tetrachloride, but separationwas not good. Subsequent re-chromatography on silica gel provided goodseparation of the two bands. The material from the first band weighed015g (72%) and was determined by mass spectrometry to bemethoxynonachloroferrocene. The material from the second band weighed0.06g (28%) and was determined by mass spectrometry to be 1,1'-dimethoxyoctach1oroferrocene. Both methoxy derivatives were soluble inall common solvents.

EXAMPLE XV] Reaction of Decachloroferrocene with Sodium Ethoxide ratioTo a solution formed by dissolving sodium metal (0.80g, 0.035 mol) inabsolute ethanol ml) was added decachloroferrocene (1.00g, 0.00190 mol).The resulting mixture was stirred and refluxed for 59 days. At intervalsduring the reaction, samples were withdrawn and analyzed by TLC, GLC andmass spectrometry. 1n the following table, the percentages, asdetermined by GLC, of starting material, monoethoxy, diethoxy, triethoxyand tetraethoxy derivatives are shown at the indicated times:

After 59 days 1,416 hours), the reaction mixture was cooled, absorbed onsilica gel, and ehromatographed. Carbon tetrachloride eluted two bandsfrom which were obtained 0.1923 (28%) of tnethoxyheptachloroferrocene asan oil and 0.480g (72%) of tetraethoxyhexachloroferrocene as an oilysolid. GLC of the triethoxy derivative showed two isomers of which therelative percentages in order of increasing retention time were 83percent and I7 percent. GLC of the tetraethoxy derivative showed threeisomers of which the relative percentages in order of increasingretention time were 59, 36 and percent.

A second reaction was conducted under the same conditions as describedabove, using 0.10 mol of sodium ethoxide. The reaction mixture wasworked up after 6 hours to give 0.8lg (67%) of1,1'-diethoxyoctachloroferrocene and 0.27g (22%) oftriethoxyheptachloroferrocene. The former compound was recrystallizedfrom hexane, giving a product having a melting point of 107 to 108 C.Analysis of the product gave Oxidative Stability of Highly ChlorinatedMetallocenes Runs were conducted to demonstrate the oxidative stabilityof highly chlorinated metallocenes.

l, l 2,2 3 ,3 4,4'-octachloroferrocene and decachloroferrocene were eachmixed with concentrated nitric acid at 23 C. Both compounds wereundissolved after 10 minutes at 100 C. in the acid.

A carbon tetrachloride solution of each compound was stirred vigorouslywith concentrated nitric acid at 23 C. for 29 hours. Theoctachloroferrocene was destroyed while the decachloroferrocene wasrecovered unchanged.

The foregoing tests demonstrate that both compounds are resistant tooxidation with decachloroferrocene being the more highly resistant ofthe two. An important facet of this property of the highly chlorinatedferrocenes is that reactions in strong oxidizing environments,impossible with conventional ferrocene derivatives, can be carried outwith these novel ferrocenes.

In another run decachlororuthenocene was dissolved in carbontetrachloride and stirred at 23 C. with concentrated nitric acid. Thecompound was recovered unchanged after 68 hours, demonstrating theenhancement in oxidation stability for another highly chlorinatedmetallocene analogous to that obtained with the ferrocene compounds. ltis noted that ruthenocene per se and ferrocene per se are both oxidizedimmediately by concentrated nitric acid.

Modifications of the present invention will become apparent to thoseskilled in the art upon consideration of the foregoing disclosure. Suchmodifications clearly come within the spirit and scope of the invention.

We claim:

1. As a new composition of matter, a polychlorinated metal loceneselected from the group of compounds having the following structuralformulas:

Cl Cl wherein M is a metal selected from the groups consisting of iron,nrthenium and osmium; R is Cl, l, methoxy, ethoxy, Li or COOl-l; and R,,R, and R are each Cl or H, the R, group being 1, 0CH,, OC,H,, Li orCOOl-l only when R,, R, and R are each Cl, and each Cl atom beingadjacent another Cl atom when R,, R orlhisCl.

2. A composition according to claim I in which a polychlorinatedmetallocene has the structure of Formula (I) in which M is iron and RR,, R,, and R are each Cl.

3. A composition according to claim 1, in which a polychlorinatedmetallocene has the structure of Formula (I) in which M is ruthenium andR 11,, R and R are each Cl.

4. A composition according to claim 1 in which a polychlorinatedmetallocene has the structure of Formula (I) in which M is iron, Risland R R, and R are each Cl.

5. A composition according to claim I in which a polychlorinatedmetallocene has the structure of Formula l in which M is iron, R, is L;and Rg, R,,and R, are each Cl.

6. A composition according to claim 1 in which a polychlorinatedmetallocene has the structure of Formula (1) in which M is iron, R isCOOH and 11,, R, and R.. are each Cl.

7. A composition according to claim I in which a polychlorinatedmetallocene has the structure of Formula (2) in which M is iron and R,and R, are each Cl.

8. A process for preparing a polychlorinated metallocene which comprisesthe following steps:

1. reacting a chlorinated metallocene selected from the group consistingof l,l'-dichloroferrocene, l,ldichlororutheneocene, l I'-dichloroosmocene, chloroferrocene, chlororutheneocene andchloroosmocene; with an organolithium compound having the formula RLi,where R is phenyl or alkyl, in the presence of a solvent for thechlorinated metallocene;

2. adding a chlorinating agent to the resulting reaction mixture; andrecovering a reaction mixture containing a l,l',2.2'metallocene selectedis a dichlorometallocene or a 1,2-dichlorometallocene when thechlorinated metallocene selected is a chloro metallocene.

9. The process according to claim 8 in which a l,l',2,2'-tetrachlorometallocene or a 1,2-dichlorometallocene is separated fromsaid reaction mixture; said l,l',2,2- tetrachlorometallocene or saidl,2-dichlorometallocene is reacted with said organolithium compound; achlorinating agent is added to the resulting reaction mixture; and asecond reaction mixture is recovered containing a l,l',2,2,3,3'-hexachlorometallocene when a l,l,2,2'-tetrachlorometallocene is areactant or a l,2,3,-trichlorometallocene when a 1,2-dichlorometallocene is a reactant.

10. The process according to claim 9 in which a l,l',2,2',3,3'-hexachlorometa.llocene or a 1,2,3-trichlorometallocene isseparated from said second reaction mixture; said l,l',2,2,3,3'-hexachlorometallocene or said 1,2,3-trichlorometallocene isreacted with said organolithium compound; a chlorinating agent is addedto the resulting reaction mixture; and a third reaction mixture isrecovered containing a l,l',2,2",4,'-octachlorometallocene when al,1',2,2',3,3 '-hexachlorometallocene is a reactant or a 1,2,3,4-tetrachlorometallocene when a l,2,3-trichlorometallocene is a reactant.

ll. The process according to claim 10 in which a l,l '.2,2'.3,3',4,4'-octachlorometallocene or a l,2,3,4-tetrachlorometallocene isseparated from said third reaction mixture; said l,l',2,2"4,4-octachlorometallocene or said l,2,3,4- tetrachlorometalloccneis reacted with said organolithium compound; a chlorinating agent isadded to the resulting reaction mixture, and a fourth reaction mixtureis recovered containing a l,l,2,2'3,3'.4,4,5,5'-decachlorometallocenewhen a l,l',2,2',3,3',4,4'-octachlorometallocene is a reactant or al,2,3,4,5pentachlorometallocene when a l,2,3,4- tetrachlorometalloceneis a reactant.

l2. The process according to claim l1 in which said fourth reactionmixture contains l l ,2,2',3,3',4,4',5,5- decachloroferrocene.

13. The process according to claim ll in which said fourth reactionmixture contains 1 l ',2,2',3,3'4,4',4,4'- decachlorouthenocene.

14. The process according to claim ll in which said fourth reactionmixture contains l.2 3,4,S-pentachloroferrocene.

[5. The process according to claim 8 in which said chlorinatedmetallocene is reacted in step I) with a complex of said organolithiumcompound and an aliphatic diamine.

16. The process according to claim l in which said organolithiumcompound is n-butyllithium and said aliphatic diamine isN,N.N',N-tetramethylethylenediamine.

[7. A process for preparing I,l,2,2.3,3',4,4',5,$'- decaehloroferroeenewhich comprlses the lollowlng steps:

lv reacting l.l -dichloroferrocene with an organolithium compound havingthe formula RLi, where R is phenyl or alkyl, in the presence of asolvent for said dichloroferrocene;

2. adding a chlorinating agent to the resulting reaction mixture;

recovering a first reaction mixture containing chlorinated ferrocenes;

separating said chlorinated ferrocenes from said first reaction mixture;

54 reacting said chlorinated ferrocenes with said organolithiurncompound in the presence ofsaid solvent;

6. adding a chlorinating agent to the resulting reaction mixture;

7. recovering a second reaction mixture containing chlorinatedferrocenes; I 8. repeating steps (4), (5), (6), (7), and (8) insuccession three additional times, using respectively, as a startingmaterial said second and a third and a fourth reaction mixturecontaining chlorinated ferrocenes;

9. recovering a fifth reaction mixture containing chlorinatedferrocenes; and

It) to 40 C., and the last lithiation and chlorination steps areconducted at a temperature in the range of about -5 to 5 C.

20. A process for preparing l,l ',2,2',3,3',4,4',$,5'-decachlororuthenocene which comprises the following steps:

I. reacting ruthenocene with an organolithium compound having theformula RLi, where R is phenyl or alkyl, in the presence of a solventfor said ruthenocene; adding a chlorinating agent to the resultingreaction mixture; recovering a first reaction mixture containingchlorinated ruthenocenes; 4. separating said chlorinated ruthenocenesfrom said first reaction mixture; reacting said chlorinated ruthenoceneswith 581d organolithium in the presence ofsaid solvent; adding achlorinating agent to the resulting reaction mixture;

7. recovering a second reaction mixture containing chlorinatedruthenocenes;

8. repeating steps (4), (5), (6) and (7) in succession four additionaltimes, using, respectively, as a starting material said second and athird, a fourth and a fifth reaction mixture, each containingchlorinated ruthenocenes;

9. recovering a sixth reaction mixture containing chlorinatedruthenocenes; and

I0. separating decachlororuthenocene from said sixth reaction mixture.

2l. A process according to claim 20 in which said organolithium compoundis n-butyllithium and said chlorinating agent is hexachloroethane.

22. A process according to claim 20 in which lithiation step l andchlorination step (2) and all subsequent lithiation and chlorinationsteps except the last lithiation and chlorination steps are conducted ata temperature in the range of about 0 to 40 C., and the last lithiationand chlorination steps are conducted at a temperature in the range ofabout 5 to 5 C.

t I t I II

2. adding a chlorinating agent to the resulting reaction mixture; andrecovering a reaction mixture containing a 1,1'' ,2,2''-tetrachlorometallocene when the chlorinated metallocene selectedis a dichlorometallocene or a 1,2-dichlorometallocene when thechlorinated metallocene selected is a chloro-metallocene.
 2. adding achlorinating agent to the resulting reaction mixture;
 2. adding achlorinating agent to the resulting reaction mixture;
 2. A compositionaccording to claim 1 in which a polychlorinated metallocene has thestructure of Formula (1) in which M is iron and R1, R2, R3, and R4 areeach Cl.
 3. A composition according to claim 1, in which apolychlorinated metallocene has the structure of Formula (1) in which Mis ruthenium and R1, R2, R3, and R4 are each Cl.
 3. recovering a firstreaction mixture containing chlorinated ruthenocenes;
 3. recovering afirst reaCtion mixture containing chlorinated ferrocenes;
 4. separatingsaid chlorinated ferrocenes from said first reaction mixture; 4.separating said chlorinated ruthenocenes from said first reactionmixture;
 4. A composition according to claim 1 in which apolychlorinated metallocene has the structure of Formula (1) in which Mis iron, R1 is I and R2, R3 and R4 are each Cl.
 5. A compositionaccording to claim 1 in which a polychlorinated metallocene has thestructure of Formula (1) in which M is iron, R1 is L; and R2, R3and R4are each Cl.
 5. reacting said chlorinated ruthenocenes with saidorganolithium in the presence of said solvent;
 5. reacting saidchlorinated ferrocenes with said organolithium compound in the presenceof said solvent;
 6. adding a chlorinating agent to the resultingreaction mixture;
 6. adding a chlorinating agent to the resultingreaction mixture;
 6. A composition according to claim 1 in which apolychlorinated metallocene has the structure of Formula (1) in which Mis iron, R1 is COOH and R2, R3 and R4 are each Cl.
 7. A compositionaccording to claim 1 in which a polychlorinated metallocene has thestructure of Formula (2) in which M is iron and R3 and R4 are each Cl.7. recovering a second reaction mixture containing chlorinatedruthenocenes;
 7. recovering a second reaction mixture containingchlorinated ferrocenes;
 8. repeating steps (4), (5), (6), (7), and (8)in succession three additional times, using respectively, as a startingmaterial said second and a third and a fourth reaction mixturecontaining chlorinated ferrocenes;
 8. repeating steps (4), (5), (6) and(7) in succession four additional times, using, respectively, as astarting material said second and a third, a fourth and a fifth reactionmixture, each containing chlorinated ruthenocenes;
 8. A process forpreparing a polychlorinated metallocene which comprises the follOwingsteps:
 9. recovering a sixth reaction mixture containing chlorinatedruthenocenes; and
 9. recovering a fifth reaction mixture containingchlorinated ferrocenes; and
 9. The process according to claim 8 in whicha 1,1'' ,2,2''-tetrachlorometallocene or a 1,2-dichlorometallocene isseparated from said reaction mixture; said1,1'',2,2''-tetrachlorometallocene or said 1,2-dichlorometallocene isreacted with said organolithium compound; a chlorinating agent is addedto the resulting reaction mixture; and a second reaction mixture isrecovered containing a 1,1'' ,2,2'', 3,3''-hexachlorometallocene when a1,1'' ,2,2''-tetrachlorometallocene is a reactant or a 1,2,3,-trichlorometallocene when a 1,2-dichlorometallocene is a reactant.10. The process according to claim 9 in which a 1,1'' ,2,2'' ,3,3''-hexachlorometallocene or a 1,2,3-trichlorometallocene is separatedfrom said second reaction mixture; said 1,1'' ,2,2'' ,3,3''-hexachlorometallocene or said 1,2,3-trichlorometallocene is reactedwith said organolithium compound; a chlorinating agent is added to theresulting reaction mixture; and a third reaction mixture is recoveredcontaining a 1,1'' ,2,2'' ,3,3'' ,4,''-octachlorometallocene when a1,1'' ,2,2'' ,3,3''-hexachlorometallocene is a reactant or a1,2,3,4-tetrachlorometallocene when a 1,2,3-trichlorometallocene is areactant.
 10. separating decachloroferrocene from said fifth reactionmixture.
 10. separating decachlororuthenocene from said sixth reactionmixture.
 11. The process according to claim 10 in which a 1,1'' ,2,2'',3, 3'' ,4,4''-octachlorometallocene or a1,2,3,4-tetrachloro-metallocene is separated from said third reactionmixture; said 1,1'' ,2,2'' ,3,3'' 4,4''-octachlorometallocene or said1,2,3,4-tetrachlorometallocene is reacted with said organolithiumcompound; a chlorinating agent is added to the resulting reactionmixture, and a fourth reaction mixture is recovered containing a 1,1'',2,2'' 3,3'' ,4,4'' ,5,5''-decachlorometallocene when a 1,1'' ,2, 2'',3,3'' ,4,4''-octachlorometallocene is a reactant or a 1,2,3,4,5-pentachlorometallocene when a 1,2,3,4-tetrachlorometallocene is areactant.
 12. The process according to claim 11 in which said fourthreaction mixture contains 1,1'' ,2,2'' ,3,3'' ,4,4'',5,5''-decachloroferrocene.
 13. The process according to claim 11 inwhich said fourth reaction mixture contains 1,1'' ,2,2'',3,3'' 4,4'',4,4''-decachlorouthenocene.
 14. The process according to claim 11 inwhich said fourth reaction mixture contains1,2,3,4,5-pentachloroferrocene.
 15. The process according to claim 8 inwhich said chlorinated metallocene is reacted in step (1) with a complexof said organolithium compound and an aliphatic diamine.
 16. The processaccording to claim 15 in which said organolithium compound isn-butyllithium and said aliphatic diamine is N,N,N'',N''-tetramethylethylenediamine.
 17. A process for preparing 1,1'',2,2'' ,3,3'' ,4,4'' ,5,5''-decachloroferrocene which comprises thefollowing steps:
 18. A process according to claim 17 in which saidorganolithium compound is n-butyllithium and said chlorinating agent ishexachloroethane.
 19. A process according to claim 17 in whichlithiation step (1) and chlorination step (2) and all subsequentlithiation and chlorination steps except the last lithiation andchlorination steps are conducted at a temperature in the range of about0* to 40* C., and the last lithiation and chlorination steps areconducted at a temperature in the range of about -5* to 5* C.
 20. Aprocess for preparing 1,1'' ,2,2'' ,3,3'' ,4,4'',5,5''-decachlororuthenocene which comprises the following steps:
 21. Aprocess according to claim 20 in which said organolithium compound isn-butyllithium and said chlorinating agent is hexachloroethane.
 22. Aprocess according to claim 20 in which lithiation step (1) andchlorination step (2) and all subsequent lithiation and chlorinationsteps except the last lithiation and chlorination steps are conducted ata temperature in the range of about 0* to 40* C., and the lastlithiation and chlorination steps are conducted at a temperature in therange of about -5* to 5* C.